Battery pack

ABSTRACT

The present disclosure relates to a battery pack, and more particularly, to a battery pack, the temperature of which is maintained within a certain range by a heating component or a heat dissipating component attached thereto.

TECHNICAL FIELD

The present disclosure relates to a battery pack, and more particularly,to a battery pack, the temperature of which is maintained within acertain range by using a heating component or a heat dissipatingcomponent attached thereto.

BACKGROUND ART

General battery packs include chargeable/dischargeable secondarybatteries.

Since such a secondary battery is charged/discharged through anelectro-chemical reaction, the battery pack is affected by an ambienttemperature condition environment. When a charge/discharge progressesunder an ultra-low temperature condition, internal reactions of thebattery pack slow down, and thus, cause a problem in that the servicelife, stability, or operation performance of the battery is decreased.

Accordingly, in an apparatus such as an electric vehicle, a lead storagebattery which is stably usable even under an environment of ultra-lowtemperatures (−30° C.) has been used as a battery. However, such a leadstorage battery had a performance, which gradually deteriorated withcharge/discharge, and a high self-discharge rate (usable for maximum ofsix months), and thus, the service life of the battery was short. Also,the lead storage battery had a great weight (12 Kg), and thus, had alimitation of decreasing the fuel efficiency of an electronic vehicle.

In comparison, Li-ion battery packs have low self-discharge rates andthus, have merits of long service life of battery (usable for maximum ofthree years) and a light weight (3 Kg). However, as described above, theLi-ion battery packs have a limitation in that operation performancethereof deteriorates under an environment of ultra-low temperatures.Thus, in order to use a Li-ion battery instead of a lead storagebattery, the problem of deteriorating operation performance under suchan environment of ultra-low temperatures should be solved.

In addition, when used for a long time, the Li-ion battery packgenerates heat. In particular, a large-capacity battery pack involvemore heat due to an increase in current quantity during charge ordischarge. At this point, when the heat generated is not sufficientlyremoved, the performance of the battery pack may deteriorate or furthercause fire or explosion. Accordingly, in order to maintain and improvethe performance of the battery pack under a high temperature condition,an alternative to decrease the internal temperature of the battery packis required.

In order to solve the problem of rise or drop of the internaltemperature of such a battery pack, in related arts, a heating componentor a heat dissipating component has been attached to a side surface of acylindrical cell in a Li-ion battery pack to thereby increase ordecrease the internal temperature of the battery pack.

Referring below to FIGS. 1 and 2 , a cylindrical cell in whichheating/heat-dissipating components according to related arts areattached to a side surface thereof will be described in detail.

FIG. 1 is a perspective view of the inside of a cylindrical cell.

FIG. 2 is an exemplary view of cylindrical cells withheating/heat-dissipating components attached to side surfaces thereof inaccordance with a related art.

Referring to FIG. 1 , a cylindrical cell has a structure in which apositive electrode base material, a negative electrode base material,and a separator are configured to be inserted into a can in a rollshape. In such a cylindrical cell structure, when a heating component isattached to a side surface of the cylindrical cell according to arelated art cell and applies heat, the applied heat is transferred viathe positive electrode base material, the negative electrode basematerial and the separator. Therefore, a problem of taking a long timeto rise the internal temperature occurs.

In addition, referring to FIG. 2 , the heating component or the heatdissipating component is attached in a zigzag shape to the side surfacesof the cylindrical cells. To assemble such a shape is difficult due to arepelling force between the heating/heat-dissipating components and aproblem of configuring a plurality of cylindrical cells occurs.

Thus, in order to maintain the operation performance of a battery packunder a high or ultra-high temperature condition, it is necessary todevelop an alternative attachment shape other than the side surfaceattachment for the heating or heat-dissipating component which adjuststhe internal temperature of the battery pack.

RELATED ART DOCUMENT

Korean Patent Application Laid-Open Publication No. 2016-0024187.

DISCLOSURE OF THE INVENTION Technical Problem

The present disclosure provides a battery pack which enables a stableoperation thereof by allowing the internal temperature thereof to beadjusted quicker than batteries of related arts when the internaltemperature thereof is a high or ultra-high temperature.

Technical Solution

In accordance with a first exemplary embodiment, a battery packconfigured to include a heating component for applying heat to aplurality of cylindrical cells, includes: an upper end cover providedabove the plurality of cylindrical cells to protect the inside thebattery pack; a first metal panel positioned below the upper end coverand jointed to the upper portion of the cylindrical cells; a secondmetal panel jointed to a lower portion of the cylindrical cells; aholder configured to surround and fix an outer side surface of theentire cylindrical cells and the lower portion of the second metalpanel; and a lower end cover positioned below the second metal panel andthe holder to form a lower end portion of the battery pack.

The heating component may be attached between the first metal panel andthe upper end cover or between the holder and the lower end cover, ormay be attached between the first metal panel and the upper end coverand between the holder and the lower end cover.

The first metal panel and the second metal panel may have high thermalconductivities.

A heating pad, a heating wire, a liquid heater, or a metal heater may beused for the heating component.

In accordance with a second exemplary embodiment, a battery packconfigured to include a heat-dissipating component for absorbing heatgenerated from a plurality of cylindrical cells, includes: an upper endcover provided above the plurality of cylindrical cells to protect theinside the battery pack; a first metal panel positioned below the upperend cover and jointed to the upper portion of the cylindrical cells; asecond metal panel jointed to a lower portion of the cylindrical cells;a holder configured to surround and fix an outer side surface of theentire cylindrical cells and the lower portion of the second metalpanel; and a lower end cover positioned below the second metal panel andthe holder to form a lower end portion of the battery pack.

The heating component may be attached between the first metal panel andthe upper end cover or between the holder and the lower end cover, ormay be attached between the first metal panel and the upper end coverand between the holder and the lower end cover.

The first metal panel and the second metal panel may have high thermalconductivities.

A heat-dissipating pad, a heat-dissipating wire, a liquid cooler, or ametal cooler may be used for the heat-dissipating component.

In accordance with a third exemplary embodiment, a battery packconfigured to include a heat-dissipating component for absorbing heatgenerated from a plurality of cylindrical cells and a heating componentfor applying heat to the plurality of cylindrical cells, includes: anupper end cover provided above the plurality of cylindrical cells toprotect the inside the battery pack; a first metal panel positionedbelow the upper end cover and jointed to the upper portion of thecylindrical cells; a second metal panel jointed to a lower portion ofthe cylindrical cells; a holder configured to surround and fix an outerside surface of the entire cylindrical cells and the lower portion ofthe second metal panel; and a lower end cover positioned below thesecond metal panel and the holder to form a lower end portion of thebattery pack.

The heat-dissipating component may be attached between the first metalpanel and the upper end cover, and the heating component may be attachedbetween the holder and the lower end cover; or the heating component maybe attached between the first metal panel and the upper end cover, andthe heat-dissipating component may be attached between the holder andthe lower end cover.

The first metal panel and the second metal panel may have high thermalconductivities.

A heating pad, a heating wire, a liquid heater, or a metal heater may beused for the heating component, and a heat-dissipating pad, aheat-dissipating wire, a liquid cooler, or a metal cooler may be usedfor the heat-dissipating component.

Advantageous Effects

A battery pack in accordance with exemplary embodiments has heatingcomponents or heat-dissipating components attached above and belowcylindrical cells, and thus, heat in the battery pack may be transferredquicker than in battery packs of related arts, a stable operation of thebattery pack may be continued, and as the battery pack including aplurality of cylindrical cells may be stably assembled, a large-capacitybattery may be easily produced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the inside of a cylindrical cell.

FIG. 2 is an exemplary view of cylindrical cells withheating/heat-dissipating components attached to side surfaces thereof inaccordance with a related art.

FIG. 3 is a perspective view of a battery pack in accordance with anexemplary embodiment.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, exemplary embodiments will be described in detail withreference to contents illustrated in accompanying drawings. However, thepresent disclosure should not be construed as limited to the exemplaryembodiments. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the present invention to those skilled in the art.

In addition, the terms including ordinal numbers such as first andsecond may be used to describe various components, but the componentsare not limited by the terms. The terms are used only for the purpose ofdiscriminating one component from other components. For example, a firstcomponent may be named as a second component within the scope of thepresent disclosure, and the second component may be nabbed as the firstcomponent. The terms used in the present disclosure are used to describeonly a specific embodiment, and are not used to limit the presentdisclosure. Singular representation includes plural representationunless otherwise noted clearly different in context.

General terms used as widely as possible at present are selected as theterms used in this disclosure while a function thereof in the disclosureis considered, but the terms may be changed according to intention ofthose skilled in the art, precedent, emergence of new technique, or thelike. In addition, in a specific case, there may also be termsarbitrarily selected by the applicant, and in this case, the meaning ofthe terms may be described in detail in the description section of thedisclosure. Thus, the terms used in this disclosure should be definednot on the basis of the simple names thereof but on the basis of themeaning thereof and contents thereof entirely over the presentdisclosure.

1. 1. Battery Pack in Accordance with First Exemplary Embodiment

A battery pack in accordance with the exemplary embodiment includes,above and below cylindrical cells, a metal panel, aheating/heat-dissipating component, and a cover in this order with thecylindrical cells disposed at the central portion of the battery pack.

FIG. 3 is a perspective view of a battery pack in accordance with anexemplary embodiment.

Referring to FIG. 3 , a battery pack 100 in accordance with a firstexemplary embodiment is a battery pack which is configured to includeplurality of cylindrical cells 140 and to have performance that can bemaintained as an appropriate operating temperature is maintained byapplying heat to the cylindrical cells 140 when the internal temperatureof the battery pack is a low temperature. The battery pack includes: anupper end cover 110 which is provided above the plurality of cylindricalcells 140, forms the appearance of the battery pack 100, and protectsthe inside thereof; a first heating component 120 which is attachedbetween the cylindrical cells 140 and the upper end cover 110 andapplies heat to the cylindrical cells 140 when the internal temperatureof the battery pack is low; a first metal panel 130 which is attachedabove the cylindrical cells 140 and electrically connected to the firstheating component 120; a second metal panel 150 attached below thecylindrical cells 140 and connected to positive electrode terminals andnegative electrode terminals of the cylindrical cells 140 through spotwelding or laser welding; a holder 160 which surrounds and fixes sidesurfaces of the cylindrical cells 140 and the lower portion of thesecond metal panel 150 and prevents a series of fire; a second heatingcomponent 170 which applies heat to the cylindrical cells 140 tomaintain the internal temperature of the battery pack, when the internaltemperature of the battery pack is low, and is attached below the secondmetal panel 150 and the holder 160; and a lower end cover 180 which ispositioned below the second heating component 170 and forms the lowerend portion of the battery pack.

Here, the first metal panel 130 and the second metal panel 150 have highthermal conductivities and thereby allow the heat generated from thefirst heating component 120 and the second heating component 170 to bequickly transferred to the cylindrical cells 140. In addition, the firstheating component 120 and the second heating component 170 may beattached between the first metal panel 130 and the upper end cover 110or between the holder 160 and the lower end cover 180, or may beattached both between the first metal panel 130 and the upper end cover110 and between the holder 160 and the lower end cover 180.

In addition, the first metal panel 130 and the second metal panel 150,which are welded to the cylindrical cells 140, are electricallyconnected not only to the first heating component 120 and the secondheating component 170 but also to a BMS (not shown) which controls theoperation of the battery pack. Such a BMS (not shown) measures theinternal temperature of the battery pack 100 and controls the firstheating component 120 and the second heating component 170 to beoperated, when the temperature of the battery pack 100 is equal to orlower than a preset reference temperature. In general, since thetemperature at which the performance of a Li-ion battery is decreased is−30° C., the preset reference temperature here is set to, for example,−10° C. to enable the battery pack to be stably operated.

In addition, the first heating component 120 and the second heatingcomponent 170 are configured in a shape so as to be respectivelyattached above and below the cylindrical cells 140 by using a heatingpad, a heating wire, a liquid heater or a metal heater. The reason forattaching the heating components 120 and 170 as such above and below thecylindrical cells 140 is because repelling forces between the heatingcomponents are weaker, the heat transfer efficiency is higher, and theattachment method is simpler than those in the zigzag side surfaceattachment shape.

2. 2. Battery Pack in Accordance with Second Exemplary Embodiment

In the second exemplary embodiment, a heat-dissipating component isattached to a battery pack 100, which is different from theabove-mentioned heating component-attached battery pack 100. Thus, whenthe internal temperature of the battery pack is high, heat ofcylindrical cells 140 is dissipated to the outside and the performanceof the battery pack may be maintained as an appropriate operatingtemperature is maintained.

As such, the battery pack 100 is configured to include: an upper endcover 110 which is positioned above a plurality of cylindrical cells140, forms the appearance of the battery pack 100, and protects theinside thereof; a first heat-dissipating component 120 which is attachedbetween the cylindrical cells 140 and the upper end cover 110 anddissipates heat of the cylindrical cells 140 to the outside when theinternal temperature of the battery pack 100 is high; a first metalpanel 130 which is attached above the cylindrical cells 140 andelectrically connected to the first heating component 120; a secondmetal panel 150 attached below the cylindrical cells 140 and connectedto positive electrode terminals and negative electrode terminals of thecylindrical cells 140 through spot welding or laser welding; a holder160 which surrounds and fixes side surfaces of the cylindrical cells 140and the lower portion of the second metal panel 150 and prevents aseries of fire; a second heat-dissipating component 170 which dissipatesheat of the cylindrical cells 140 to thereby maintain the internaltemperature of the battery pack, when the internal temperature of thebattery pack is high, and is attached below the second metal panel 150and the holder 160; and a lower end cover 180 which is positioned belowthe second heating component 170 and forms the lower end portion of thebattery pack.

Here, the first metal panel 130 and the second metal panel 150 have highthermal conductivities and thereby allow the heat generated from thecylindrical cells 140 to be quickly transferred to the firstheat-dissipating component 120 and the second heat-dissipating component170.

In addition, the first heat-dissipating component 120 and the secondheat-dissipating component 170 may be attached between the first metalpanel 130 and the upper end cover 110 or between the holder 160 and thelower end cover 180, or may be attached both between the first metalpanel 130 and the upper end cover 110 and between the holder 160 and thelower end cover 180.

In addition, the first metal panel 130 and the second metal panel 150,which are welded to the cylindrical cells 140, are electricallyconnected not only to the first heat-dissipating component 120 and thesecond heat-dissipating component 170 but also to a BMS (not shown)which controls the operation of the battery pack. Such a BMS (not shown)measures the internal temperature of the battery pack 100 and controlsthe first heat-dissipating component 120 and the second heat-dissipatingcomponent 150 to be operated, when the temperature of the battery pack100 is equal to or higher than a preset reference temperature. Ingeneral, since the temperature at which the performance of a Li-ionbattery is decreased is 30° C., the preset reference temperature here isset to, for example, 20° C. to enable the battery pack to be stablyoperated.

In addition, the first heat-dissipating component 120 and the secondheat-dissipating component 150 are configured in a shape so as to berespectively attached above and below the cylindrical cells 140 by usinga heat-dissipating pad, a heat-dissipating wire, a liquid cooler or ametal cooler. The reason for attaching the heat-dissipating components120 and 150 as such above and below the cylindrical cells 140 is becauserepelling forces between the heating components are weaker, the heattransfer efficiency is higher, and the attachment method is simpler thanthose in the zigzag side surface attachment shape.

3. 3. Battery Pack in Accordance with Third Exemplary Embodiment

In the third exemplary embodiment, a heating component and aheat-dissipating component are simultaneously attached to a battery pack100, which is different from the above-mentioned battery packs 100 towhich a heating component and a heat-dissipating component arerespectively attached. When the internal temperature of the battery packis out of a preset reference range, heat is applied to the cylindricalcells 140 or heat of cylindrical cells 140 is dissipated to the outside,and the performance of the battery pack can thereby be maintained as anoperating temperature is maintained.

As such, the battery pack 100 is configured to include: an upper endcover 110 which is positioned above a plurality of cylindrical cells140, forms an appearance of the battery pack 100, and protects theinside thereof; a heat-dissipating component 120 which is attachedbetween the cylindrical cells 140 and the upper end cover 110 anddissipates heat of the cylindrical cells 140 to the outside when theinternal temperature of the battery pack 100 is high; a first metalpanel 130 which is attached above the cylindrical cells 140 andelectrically connected to the first heating component 120; a secondmetal panel 150 attached below the cylindrical cells 140 and connectedto positive electrode terminals and negative electrode terminals of thecylindrical cells 140 through spot welding or laser welding; a holder160 which surrounds and fixes side surfaces of the cylindrical cells 140and the lower portion of the second metal panel 150 and prevents aseries of fire; a heating component 170 which applies heat to thecylindrical cells 140 to thereby maintain the internal temperature thebattery pack 100, when the internal temperature of the battery pack 100is low, and is attached below the second metal panel 150 and the holder160; and a lower end cover 180 which is positioned below the heatingcomponent 170 and forms the lower end portion of the battery pack 100.

Here, the first metal panel 130 and the second metal panel 150 have highthermal conductivities and thereby allow the heat generated from thecylindrical cells 140 and the heating component 170 to be quicklytransferred.

In addition, the heat-dissipating component 120 may be attached betweenthe first metal panel 130 and the upper end cover 110, and the heatingcomponent 170 may be attached between the holder 160 and the lower endcover 180. Alternatively, the heating component 120 may be attachedbetween the first metal panel 130 and the upper end cover 110 and theheat-dissipating component 120 may be attached between the holder 160and the lower end cover 180.

In addition, the first metal panel 130 and the second metal panel 170,which are welded to the cylindrical cells 140, are electricallyconnected not only to the heat-dissipating component 120 and the heatingcomponent 170 but also to a BMS which controls the operation of thebattery pack. Such a BMS measures the internal temperature of thebattery pack 100 and controls the heat-dissipating component 120 to beoperated, when the temperature of the battery pack 100 is equal to orlower than a first preset reference temperature, and controls theheating component 150 to be operated, when the temperature of thebattery pack 100 is equal to or higher than a second preset referencetemperature. In general, since the temperature at which the performanceof a Li-ion battery is decreased is lower than −30° C. or equal to orhigher than 30° C., the first preset reference temperature here is setto, for example, −5° C., and the second preset reference temperature isset to, for example, −15° C. to enable the battery pack to be stablyoperated.

In addition, a heating pad, a heating wire, a liquid heater or a metalheater is used for the heating component 150, and a heat-dissipatingpad, a heat-dissipating wire, a liquid cooler or a metal cooler is usedfor the heat-dissipating component 120. The reason for attaching theheat-dissipating component 120 and the heating component 150 as suchabove and below the cylindrical cells 140 is because repelling forcesbetween the heating components are weaker, the heat transfer efficiencyis higher, and the attachment method is simpler than those in the zigzagside surface attachment shape. In addition, the reason for disposing theheat-dissipating component 120 above the cylindrical cells 140 anddisposing the heating component 150 below the circular dells 140 isbecause the battery pack should be configured such that heat generatedfrom the cylindrical cells 140 is moved upward so as to be dischargeableto the outside through the heat-dissipating component 120, and heatgenerated from the heating component 150 may be applied to thecylindrical cells 140.

Although the technical concept of the present invention has beenspecifically described according to the above exemplary embodiments, itshould be understood that the above embodiments are provided not tolimit but to describe the technical concepts. Furthermore, those skilledin the art relating to technical field of the present disclosure mayrealize various embodiments within the techniques set forth in claims.

What is claimed is:
 1. A battery pack comprising: a plurality of cylindrical cells, the plurality of cylindrical cells including exterior cells arranged at an outer periphery as outermost cells from among plurality of cylindrical cells and interior cells arranged at interior locations as inner cells from among the plurality of cylindrical cells; an upper end cover provided above the plurality of cylindrical cells to protect the inside of the battery pack; a first metal panel positioned below the upper end cover and welded to the upper portion of the plurality of cylindrical cells; a second metal panel welded to a lower portion of the plurality of cylindrical cells; a holder configured to surround an outer side surface of the plurality of cylindrical cells as a whole by encircling the plurality of cylindrical cells at the exterior cells, and to fix the plurality of the cylindrical cells to the lower portion of the second metal panel, wherein, among the exterior cells and the interior cells of the plurality of cylindrical cells, the holder directly contacts only the exterior cells of the plurality of cylindrical cells; a lower end cover positioned below the second metal panel and the holder to form a lower end portion of the battery pack; and a heat-dissipating component for absorbing heat generated from the plurality of cylindrical cells and a heating component for applying heat to the plurality of cylindrical cells, wherein the heat-dissipating component is attached between the first metal panel and the upper end cover, and the heating component is attached between the second metal panel and the lower end cover, wherein the first metal panel and the second metal panel are electrically connected to the heat-dissipating component and the heating component, respectively, wherein the second metal panel is interposed between the heating component and the plurality of cylindrical cells, and directly contacts the heating components, wherein the heating component directly heats the second metal panel, and heat is transferred through the second metal panel to directly heat the plurality of cylindrical cells, wherein the heating component is electrically connected to a battery management system (BMS), and wherein the BMS is configured to measure an internal temperature of the battery pack and control the heating component.
 2. The battery pack of claim 1, wherein the first metal panel and the second metal panel have high thermal conductivities.
 3. The battery pack of claim 1, wherein a heating pad, a heating wire, a liquid heater, or a metal heater is used for the heating component, and a heat-dissipating pad, a heat-dissipating wire, a liquid cooler, or a metal cooler is used for the heat-dissipating component.
 4. The battery pack of claim 1, wherein the first metal panel and the second metal panel are further electrically connected to the BMS that measures the internal temperature of the battery pack. 